In the first sign of possible change in Republican orthodoxy, potential 2012 presidential hopeful Haley Barbour is speaking out against nation-building - a central focus of U.S. foreign policy for nearly two decades and of President George W. Bush’s administration.

“What are we doing in Libya?” Mr. Barbour, a former national party chairman, said last week. “I mean, we have to be careful in my mind about getting into nation-building exercises, whether it’s in Libya or somewhere else. We’ve been in Afghanistan 10 years.”

The Mississippi governor is also calling for what, aside from the party’s libertarian wing, has been the unthinkable for decades among Republicans in general and conservative defense hawks in particular - cutting Pentagon spending.

“We can save money on defense, and if we Republicans don’t propose saving money on defense, we’ll have no credibility on anything else,” he told an Iowa audience.

As a second-term governor, a former political director in the Reagan White House, a former Washington lobbyist and a former Republican National Committee chairman, Mr. Barbour is the personification of his party’s establishment yet has staked out a position directly opposed to the party’s powerful neoconservative wing.

“It is amazing to me that a Republican establishment figure like Haley Barbour is finally questioning the neoconservative influence over Republican foreign-policy decision-making,” former Texas GOP Chairman Tom Pauken said. “It is about time we realized that U.S. use of military force to impose ‘democracy’ in the Middle East has not worked and will not work.”

Mr. Barbour’s views on nation-building and military spending have drawn exceptionally sharp, even condescending, criticism from Republicans who have been adamant supporters of U.S. military intervention abroad, including regime change, as a tool of foreign policy and to promote American values.

Leading neoconservative voice and Weekly Standard editor William Kristol called Mr. Barbour’s stand “childish” and “slightly offensive,” and said it “raises the question of how much time Barbour has spent at the Pentagon - apart from time spent lobbying for defense contractors or foreign governments.”

David Horowitz, a prominent member of the party’s neoconservative wing, said his own views are changing and he has come around to Mr. Barbour’s position.

“I agree with Haley Barbour and am not surprised that he too has come to this conclusion,” Mr. Horowitz said. “Afghanistan is now our longest war, in large part because we are trying to remake a nation which has barely emerged from the seventh century, and in many respects has not. It was our mistake in Iraq.”

Mr. Kristol called Mr. Barbour “a shrewd political operative” and said his stance may reflect deeper political shifts in the party.

“If he’s saying this, he’s seeing an opening for a defense-cutting, Afghanistan-skeptic candidate in 2012,” Mr. Kristol said. “Polls suggest he may be right - however irresponsible Barbour’s pandering to these sentiments may be - though history also suggests that, so far, Republicans have been inclined to nominate a foreign-policy hawk, not an advocate of U.S. retreat.”

GOP campaign strategist Mike Murphy said he agrees that Mr. Barbour’s views “may be a leading indicator in the primary of a sentiment that may be growing.”

Former House Speaker Newt Gingrich, another potential 2012 GOP presidential nomination contender, said the Pentagon budget should be expanded, not cut, and that Americans need to come to grips with the fact that actions such as the mission in Libya will take time.

“We need a larger Pentagon budget to reinvest in capabilities to maintain our superiority over China while sustaining the forces engaged” elsewhere, Mr. Gingrich said. “The Obama administration needs to submit a supplemental to pay for its Libyan war.”

A spokeswoman for Indiana Gov. Mitch Daniels, another potential presidential contender, referred to statements Mr. Daniels delivered at the Conservative Political Action Conference in February, in which he appeared to favor defense cuts while defending the nation-building and regime-change policies practiced when Mr. Daniels was the top budget adviser in the Bush White House.

“Nothing, not even the first and most important mission of government, our national defense, can get a free pass,” Mr. Daniels said at CPAC. “I served in two administrations that practiced and validated the policy of peace through strength. It has served America and the world with irrefutable success.”

But, he added, “if our nation goes over a financial Niagara, we won’t have much strength and, eventually, we won’t have peace.”

People who supported spreading democracy and changing regimes, by force if necessary, failed to dominate the administration of President George H.W. Bush, a Republican, who limited U.S. action to liberating Kuwait while resisting pressure to topple Iraqi dictator Saddam Hussein.

But President Clinton, a Democrat, pursued nation-building with U.S. military action in the Balkans and Haiti. Upon taking office, President Obama surrounded himself with proponents of spreading democracy abroad.

“Now, as president-elect he has just formed the most conservative foreign-policy team since John F. Kennedy, one well to the right of Bill Clinton,” Mr. Horowitz said in 2009, in scolding other neoconservatives for questioning Mr. Obama’s will to pursue regime change. “Where is your gratitude for that?”